CN111868845A

CN111868845A - Composition for impregnating paper sleeves

Info

Publication number: CN111868845A
Application number: CN201980019783.9A
Authority: CN
Inventors: C·贝瑟尔; H·维尔拜尔斯; D·巴尔
Original assignee: Huntsman Advanced Materials Licensing Switzerland GmbH
Current assignee: Huntsman Advanced Materials Licensing Switzerland GmbH
Priority date: 2018-03-16
Filing date: 2019-02-22
Publication date: 2020-10-30
Also published as: HUE056683T2; PL3766084T3; KR20200133362A; MX2020009609A; WO2019174891A1; BR112020018507A2; US11718706B2; CA3091585A1; US20210024684A1; JP2021518481A; EP3766084A1; EP3766084B1; PH12020551416A1; JP7341174B2; ES2899154T3

Abstract

The invention relates to a curable mixture for use in impregnating paper bushings, said mixture comprising a resin mixture of bisphenol a-diglycidyl ether (BADGE) and bisphenol F-diglycidyl ether (BFDGE), methyltetrahydrophthalic anhydride (MTHPA) as hardener, and an accelerator selected from the group consisting of tertiary alkylamine amino alcohols and their corresponding ethers; as well as a paper sleeve impregnated with such a mixture and the use of such a mixture.

Description

Composition for impregnating paper sleeves

Technical Field

The present invention relates to compositions for use in impregnated paper sleeves, paper sleeves impregnated with such compositions and the use of such compositions.

Background

Resin Impregnated Paper (RIP) bushings are used, for example, in high voltage devices, such as high voltage switchgears or transformers.

The conductive core of such a bushing is typically wound with paper, with an electroplated object interposed between adjacent paper windings. A curable liquid resin/hardener mixture is then introduced into the assembly to impregnate the paper and subsequently cured.

There are numerous patents on RIP bushings of this type, for example EP 1798740 a 1.

US 3,271,509 a describes electrical insulation and bushings comprising several layers of a cellulosic sheet containing 0.02-10% by weight of a mixture of melamine and dicyandiamide, wherein the ratio of melamine to dicyandiamide is 1-5:1-4, combined with non-melting agglomerates resulting from the reaction of an epoxy resin, preferably 3, 4-epoxy-6-methylcyclohexylmethyl-3, 4-epoxy-methylcyclohexaneformate or dicyclopentadiene dioxide, with 10-60 parts of maleic anhydride crosslinker per 100 parts of epoxy resin. Other cross-linking agents may be, for example, dodecenyl succinic anhydride, trimellitic anhydride, or hexahydrophthalic anhydride. However, such impregnation systems are relatively expensive.

US 2015/0031789 a1 relates to a composite material for use in a high voltage device having a high voltage electrical conductor, which material at least partly serves for grading the electric field of the high voltage electrical conductor and comprises a polymer matrix and fibers embedded therein.

It is also known that a mixture of bisphenol a-diglycidyl ether (BADGE), methylhexahydrophthalic anhydride (MHHPA), and Benzyldimethylamine (BDMA) is used to produce RIP bushings.

Another known system for producing RIP bushings is based on BADGE, mixed with a hardener composition containing hexahydrophthalic anhydride (HHPA) and MHHPA.

However, for health and environmental reasons, it is desirable to have an impregnation system that does not contain MHHPA, which is classified as SVHC (a substance of very high interest) in REACH regulations.

Object of the Invention

A potential object of the present invention is to provide an impregnating material for impregnating paper sleeves, in particular for high-pressure applications, which is free of MHHPA and any other material marked as toxic, and which maintains the same positive properties as known systems, such as Tg of 100-.

Disclosure of Invention

Unless otherwise defined herein, technical terms used in connection with the present invention shall have meanings that are commonly understood by those of ordinary skill in the art. Furthermore, unless the context requires otherwise, singular terms shall include the plural and plural terms shall include the singular.

All patents, published patent applications, and non-patent publications mentioned in the specification are indicative of the level of skill of those skilled in the art to which the invention pertains. All patents, published patent applications, and non-patent publications cited in any section of this application are expressly incorporated by reference in their entirety to the same extent as if each individual patent or publication were specifically and individually indicated to be incorporated by reference to the extent not inconsistent with the present invention.

All of the compositions and/or methods disclosed herein can be made and executed without undue experimentation in light of the present disclosure. While the compositions and methods of this invention have been described in terms of preferred embodiments, it will be apparent to those of ordinary skill in the art that variations may be applied to the compositions and/or methods and in the steps or in the sequence of steps of the methods described herein without departing from the concept, spirit and scope of the invention. All such similar substitutes and modifications apparent to those skilled in the art are deemed to be within the spirit, scope and concept of the invention.

As utilized in accordance with the present invention, the following terms, unless otherwise indicated, shall be understood to have the following meanings.

The use of the word "a" or "an" when used in conjunction with the terms "comprising," including, "" having, "or" containing "(or variations of such terms) can mean" one "or" an, "but it is also consistent with the meaning of" one or more, "" at least one, "and" one or more than one.

The use of the term "or" is intended to mean "and/or" unless explicitly indicated to refer only to the alternative and only if the alternatives are mutually exclusive.

Throughout the present invention, the term "about" is used to indicate that an inherent variation in error of a quantification apparatus, mechanism or method, or an inherent variation existing in an object to be measured, is included. For example, and without limitation, where the term "about" is used, the specified value referred to may vary by +/-10%, or 9%, or 8%, or 7%, or 6%, or 5%, or 4%, or 3%, or 2%, or 1%, or one or more fractions therebetween.

The use of "at least one" is to be understood to include any amount of one and more than one, including but not limited to 1, 2, 3, 4, 5, 10, 15, 20, 30, 40, 50, 100, etc. The term "at least one" may be extended by as much as 100 or 1000 or more/more depending on the term it refers to. In addition, the amount of 100/1000 should not be considered limiting, as lower or higher limits may also produce satisfactory results.

As used herein, the words "comprising," "having," "including," or "containing" and any forms thereof are inclusive or open-ended and do not exclude additional unrecited elements or method steps.

As used herein, the terms "or combinations thereof" and combinations thereof "refer to all permutations and combinations of the listed items preceding the term. For example, "A, B, C or a combination thereof" is intended to include at least one of: A. b, C, AB, AC, BC, or ABC, and in certain cases when order is important, BA, CA, CB, CBA, BCA, ACB, BAC, or CAB. Continuing with this example, expressly included are combinations that contain repetitions of one or more items or terms, such as BB, AAA, CC, AABB, AACC, abccc, CBBAAA, CABBB, and the like. The skilled person will understand that there is generally no limitation to the number of items or terms in any combination, unless otherwise apparent from the context. Likewise, when used with the phrase "selected from" or "selected from the group consisting of … …, the terms" or combinations thereof "and combinations thereof" refer to all permutations of the listed items before the phrase.

The terms "in one embodiment," "in an embodiment," "according to one embodiment," and the like generally mean that a particular feature, structure, or characteristic described later in the term is included in at least one embodiment of the invention, and may be included in more than one embodiment of the invention. Importantly, such terms are non-limiting and do not necessarily refer to the same embodiment, but may undoubtedly refer to one or more previous and/or subsequent embodiments. For example, in the following claims, any of the claimed embodiments may be used in any combination.

The phrase "substantially free of" should be used herein to mean present in an amount of less than 1 wt.%, or less than 0.1 wt.%, or less than 0.01 wt.%, or alternatively less than 0.001 wt.%, based on the total weight of the composition referred to.

The term "ambient temperature" as used herein refers to the temperature surrounding the working environment (e.g., the temperature of the area, building or room in which the curable composition is used), and does not include any temperature changes that occur as a result of direct application of heat to the curable composition to promote curing. Ambient temperatures are typically between about 10 ℃ and about 30 ℃, more specifically between about 15 ℃ and about 25 ℃. The term "ambient temperature" is used interchangeably herein with "room temperature".

Turning to the present invention, the above problems are solved by a curable mixture comprising a resin mixture of bisphenol a-diglycidyl ether (BADGE) and bisphenol F-diglycidyl ether (BFDGE), methyltetrahydrophthalic anhydride (MTHPA) as hardener, and an accelerator selected from tertiary alkylamine amino alcohols and/or their corresponding ethers.

Non-limiting examples of tertiary alkylamine aminoethanol and/or its corresponding ether include N, N ' -trimethyl-N ' -hydroxyethyl-bisaminoethyl ether, N- (3-dimethylaminopropyl) -N, N-diisopropanolamine, N-bis (3-dimethylaminopropyl) -N-isopropanolamine, 2- (2-dimethylaminoethoxy) ethanol, N ' -trimethylaminoethyl-ethanolamine, N-dimethylethanolamine, or combinations thereof.

In a preferred embodiment, the epoxy index according to ISO 3001 BADGE is in the range of 3 to 5eq/kg, preferably in the range of 3.5 to 4.5 eq/kg.

Preferably, the BFDGE has an epoxy index according to ISO 3001 in the range of 5 to 6.45eq/kg, preferably in the range of 5.3 to 6.3 eq/kg.

In one embodiment of the invention, the BADGE and BFDGE are present in the resin mixture in a weight ratio of 1:10 to 10: 1.

In a preferred embodiment, the mixture contains MTHPA in an amount corresponding to 80 to 120 wt.%, based on the stoichiometric amount of the resin mixture, even more preferably in an amount corresponding to the stoichiometric amount of the resin mixture. Stoichiometric amounts based on the resin mixture mean that 1 equivalent of MTHPA is added to 1 equivalent of the epoxy resin, i.e. BADGE plus BFDGE.

Preferably, the curable mixture contains the accelerator in an amount of <0.2pbw based on 100pbw of the resin mixture, more preferably in an amount of 0.01 to 0.10pbw based on 100pbw of the resin mixture.

In a particular embodiment, the accelerator is selected from N, N ' -trimethyl-N ' -hydroxyethyl-bisaminoethyl ether, N- (3-dimethylaminopropyl) -N, N-diisopropanolamine, N-bis (3-dimethylaminopropyl) -N-isopropanolamine, 2- (2-dimethylaminoethoxy) ethanol, N ' -trimethylaminoethyl-ethanolamine, N-dimethylethanolamine, or combinations thereof; and is preferably N, N '-trimethyl-N' -hydroxyethyl-bisaminoethyl ether.

The curable mixture of the invention may contain additional components such as, for example, processing aids, defoamers, rheological additives, wetting agents, colorants, and diluents. Notably, the disclosed compositions are substantially free of fibers, including nanofibers.

The present invention also relates to a paper sleeve impregnated with the presently disclosed composition.

In one embodiment, the paper sleeve is a sleeve for high voltage applications.

Finally, the invention relates to the use of the presently disclosed mixtures as impregnation systems for paper sleeves, in particular for high pressure applications.

The main feature of the present invention is the novel use of MTHPA as the main hardener component in the composition for impregnating the paper sleeve. The MTHPA used in the presently disclosed curable mixture may be any isomer of MTHPA or mixture thereof with a purity of > 99%.

Further, one of the main components of the presently disclosed curable mixture is a resin mixture comprising (i) BADGE having an epoxy index of 3 to 5eq/kg and (ii) BFDGE having an epoxy index of 5 to 6.45eq/kg as main resin components. The term "epoxy index" as used herein refers to the number of moles of epoxy groups per kg of resin. In the indicated range of the epoxy index, the resin contains at least a portion of longer molecules, i.e., molecules having more than one bisphenol unit. This particular choice leads to superior properties of the cured product, as can be seen in more detail in the examples.

In the case of such compositions, it is preferred that the accelerator used is one that can be used in an amount that is sufficiently low to not excessively accelerate curing and exothermic release, and, on the other hand, to accelerate curing of the resin and anhydride to achieve the desired high Tg of about 100-130 deg.C, more specifically 120-130 deg.C. Thus, a particularly preferred embodiment comprises the use of N, N ' -trimethyl-N ' -hydroxyethyl-bisaminoethyl ether or similar amines, such as for example N- (3-dimethylaminopropyl) -N, N-diisopropanolamine, N-bis (3-dimethylaminopropyl) -N-isopropanolamine, 2- (2-dimethylaminoethoxy) ethanol, N ' -trimethylaminoethyl-ethanolamine or N, N-dimethylethanolamine in an amount of <0.2pbw based on 100pbw of resin.

Further details and advantages will become apparent from the following examples. The components used therein are as follows, all available from Huntsman corporation or subsidiary thereof (TX, Woodlands):

MY 740 resin: BADGE with an epoxy index (ISO 3001) of 5.25 to 5.55eq/kg

HY1102 hardener: MHHPA

Accelerator DY 062 Accelerator: BDMA

XB 5860: BADGE-based resin formulation containing 3-7% by weight of 4,4' -methylene-bis [ N, N-bis (2, 3-epoxypropyl) aniline ]

HY 1235 hardener: mixture of HHPA and MHHPA

HY 918-1 curing agent: mixtures of the various isomers of MTHPA having a viscosity of 50 to 80mPas at 25 ℃ according to ISO 12058

GY 280 resin: BADGE with an epoxy index (ISO 3001) of 3.57 to 4.45eq/kg

GY 281 resin: bisphenol F-diglycidyl ether (BFDGE) having an epoxy index (ISO 3001) of 5.80 to 6.30eq/kg

ZF 10 accelerator: n, N, N '-trimethyl-N' -hydroxyethyl-bisaminoethyl ether

Examples

Comparative example 1(BADGE/MHHPA/BDMA)

200g of the powder

The MY 740 resin was placed in a metal reactor. Then 180g of

HY1102 hardener and 0.1g Accelerator DY 062 Accelerator. The components were then mixed using an anchor stirrer at ambient temperature for about 15 min. Finally, the reactor is subjected to a vacuum to remove all or substantially all of the bubbles from the mixture.

The mixture was then analyzed to determine its viscosity and gel time.

A portion of the mixture was then poured into a mold (preheated to 80 ℃) to prepare test specimens for mechanical and electrical testing.

The mold was processed according to the curing procedure as indicated in the table below.

After cooling to ambient temperature, Tg, mechanical and electrical properties were determined according to standard procedures as specified below.

Comparative example 2(XB 5860 +

HY 1235 hardener)

200g of XB 5860 was placed in a metal reactor. Then 170g of

HY 1235 as hardening agent. The components were then mixed using an anchor stirrer at ambient temperature for about 15 min. Finally, the reactor is subjected to a vacuum to remove all or substantially all of the bubbles from the mixture.

The mixture was then analyzed to determine viscosity and gel time.

After cooling to ambient temperature, Tg, mechanical and electrical properties were determined according to the same standard procedure as comparative example 1.

Comparative example 3(

MY 740 treeFat or blood

HY 918-1 hardener/0.05 pbwBDMA)

200g of the powder

The MY 740 resin was placed in a metal reactor. Then 170g of

HY918-1 hardener and 0.1g Accelerator DY 062 Accelerator. The components were then mixed using an anchor stirrer at ambient temperature for about 15 min. Finally, the reactor is subjected to a vacuum to remove all or substantially all of the bubbles from the mixture.

The mixture was then used to determine viscosity and gel time.

Comparative example 4(

MY 740 resin-

HY918-1 hardener/0.2 pbwBDMA)

200g of the powder

The MY 740 resin was placed in a metal reactor. Then 170g of

HY918-1 hardener and 0.4g Accelerator DY 062 Accelerator. The components were then mixed at ambient temperature using an anchor stirrerAnd 15 min. Finally, the reactor is subjected to a vacuum to remove all or substantially all of the bubbles from the mixture.

The mixture was then used to determine viscosity and gel time.

Example 1

160g of the powder

GY 280 resin and 40g

GY 281 resin was placed in a metal reactor. Then, 180g of the solution was added

HY 918-1 hardener and 0.14g

ZF 10 accelerator. The components were then mixed using an anchor stirrer at ambient temperature for about 15 min. Finally, the reactor is subjected to a vacuum to remove all or substantially all of the bubbles from the mixture.

The mixture was then used to determine viscosity and gel time.

The formulations and the results of the various measurements are shown in the following table.

Tensile strength and elongation at break were determined at 23 ℃ according to ISO R527.

Flexural strength was determined at 23 ℃ according to ISO 178.

Has a unit of

K of_IC(Critical stress intensity factor) and G in J/m2 _ICThe (specific energy to break) was determined by a bent notch test at 23 ℃.

The Tg is determined according to ISO 6721/94.

Tan is measured according to IEC 60250.

Comparative example 1 shows the most widely used system in the industry: BADGE/MHHPA/BDMA. The main problem of comparative example 1 is the REACH problem with MHHPA and the fact that the promoter BDMA is considered toxic. Furthermore, there is a need to reduce tan and further reduce viscosity as required by new standards to achieve easier impregnation.

Comparative example 2 is a system that avoids the toxicity problem of BDMA, but also contains MHHPA. Therefore, it is not a solution to the main problem. Furthermore, it has an even higher tan compared to comparative example 1.

The simplest idea for the person skilled in the art to formulate a RIP system would be to replace BADGE/MHHPA/BDMA with only MTHPA instead of MHHPA. But comparative example 3 shows that this will not work as the Tg will obviously be too low.

By increasing the amount of BDMA, the Tg can be raised to the desired level, but then the reactivity increases too much, and such systems will obviously be too reactive to be used for the intended application such as impregnation systems like resin impregnated paper sleeves (the reaction enthalpy will be released too quickly to allow it to disappear, and thus the material temperature will rise too high, which leads to overheating and cracking).

Example 1 of the present invention shows a way to function in various aspects. Combining selected types of BADGE and BFDGE to form a resin mixture and curing the resin mixture with MTHPA, from a minor amount of (A)<0.2%) tertiary alkylamine aminoethanol or ethers thereof, such as the preferred catalyst

The ZF 10 accelerator replaces BDMA to promote, resulting in a cost effective system with low viscosity and low enough reactivity to prevent overheating in the final application, resulting in>Tg of 120 ℃ provides<A desired low tan of 0.3% and is free of materials currently labeled as toxic substances, such as MHHPA and free bisphenol a. The absence of such toxic materials should render the presently disclosed compositions REACH compliant. In addition, the presently disclosed composition gives better mechanical properties than the most widely used system at present of comparative example 1.

The above-disclosed subject matter is to be considered illustrative, and not restrictive, and the appended claims are intended to cover all such modifications, enhancements, and other embodiments, which fall within the true scope of the present invention. Thus, to the maximum extent allowed by law, the scope of the present invention is to be determined by the broadest permissible interpretation of the following claims and their equivalents, and shall not be restricted or limited by the foregoing detailed description.

Claims

1. A curable mixture for use in impregnating a paper sleeve, comprising (i) a resin mixture comprising bisphenol a-diglycidyl ether (BADGE) and bisphenol F-diglycidyl ether (BFDGE), (ii) methyltetrahydrophthalic anhydride (MTHPA) as a hardener, and (iii) an accelerator selected from tertiary alkylamine amino alcohols and/or their corresponding ethers.

2. The curable mixture of claim 1, wherein the BADGE has an epoxy index according to ISO 3001 in the range between 3 and 5 eq/kg.

3. The curable mixture of claim 2, wherein the BADGE has an epoxy index according to ISO 3001 in the range between 3.5 and 4.5 eq/kg.

4. The curable mixture of any preceding claim, wherein the BFDGE has an epoxy index according to ISO 3001 in the range between 5 and 6.45 eq/kg.

5. The curable mixture of claim 4, wherein the BFDGE has an epoxy index according to ISO 3001 in the range between 5.3 and 6.3 eq/kg.

6. The curable mixture of any preceding claim, wherein the BADGE and the BFDGE are present in the resin mixture in a weight ratio of 1:10 to 10: 1.

7. Curable mixture according to any of the preceding claims, wherein the curable mixture contains MTHPA in an amount corresponding to 80 to 120 wt. -%, based on the stoichiometric amount of the resin mixture.

8. The curable mixture according to claim 7, wherein the curable mixture contains MTHPA in an amount corresponding to a stoichiometric amount based on the resin mixture.

9. The curable mixture of any one of the preceding claims, wherein the curable mixture contains the accelerator in an amount of <0.2pbw based on 100pbw of the resin mixture.

10. The curable mixture of claim 9, wherein the curable mixture contains the accelerator in an amount of 0.01 to 0.10pbw based on 100pbw of the resin mixture.

11. The curable mixture of any preceding claim, wherein the accelerator is selected from N, N ' -trimethyl-N ' -hydroxyethyl-bisaminoethyl ether, N- (3-dimethylaminopropyl) -N, N-diisopropanolamine, N-bis (3-dimethylaminopropyl) -N-isopropanolamine, 2- (2-dimethylaminoethoxy) ethanol, N ' -trimethylaminoethyl-ethanolamine, N-dimethylethanolamine, or combinations thereof.

12. The curable mixture of claim 11, wherein the accelerator is N, N '-trimethyl-N' -hydroxyethyl-bisaminoethyl ether.

13. A paper sleeve impregnated with the composition of any one of the preceding claims.

14. The paper sleeve of claim 13, wherein the paper sleeve is a sleeve for high voltage applications.

15. Use of a mixture according to any one of claims 1 to 10 as an impregnation system for paper sleeves, in particular for high pressure applications.